Five technologies on the way to net zero
If Switzerland wants to achieve its target of zero net greenhouse gas emissions by 2050, it will have to rely on the use of negative emission technologies (NET), i.e. processes that remove CO2 from the atmosphere and store it in the long term. Although NETs can in principle help to achieve the climate goals, much is still unclear at present. This is because some of these processes are still untested in practice, technically complex, costly or cannot be used on a large scale for the time being. In addition, many people know little about both the possibilities and the limitations of NET. On behalf of TA-SWISS, researchers from the Öko-Institut and Empa have therefore evaluated five NETs that are relevant for Switzerland, with the involvement of other experts. The results showed that one single process is not enough, all NETs are needed. Furthermore, the reduction of CO2 emissions must remain central. After all, avoiding emissions is cheaper than subsequently removing CO2 from the air.
The TA-Swiss study aims to inform policy-makers and the public about the opportunities, limits and risks of different methods for CO2 extraction and storage. Aspects such as feasibility, climate effectiveness, costs, resource consumption and impacts on the environment and population were considered.
The five technologies are:
- the storage of CO2 as biomass in forests and the use of wood
- storage in the form of humus in the soil and the use of plant carbon
- capture and storage of CO2 from biomass combustion (BECCS)
- removal from the air and storage (DACCS)
- the accelerated weathering of demolition concrete and rock (carbonation)
Each of the five NETs was assessed based on the current state of knowledge and with the help of expert interviews. Potential opportunities, risks, synergies and conflicts were identified and considered from a system perspective. Based on this, general and specific, technology-related options for action and recommendations were derived and reflected on together with selected stakeholders.
The most important general recommendations of the study
In order for NET’s contribution to the net-zero target to be implemented in an environmentally and socially compatible manner, politics and society should address the issue at an early stage. This requires in particular that the public is involved in shaping the conditions of use of NET by means of fact-based and comprehensible information.
There is a need for an overarching strategy for the use of limited resources, such as renewable energy, water, biomass and soil, and for financing for the development and implementation of NET.
Further research is needed to determine the potential of the different technologies.
It must be possible to record the amount of CO2 removed from the atmosphere in the long term in a transparent and simple way to create a reliable assessment framework and avoid counting the same CO2 more than once.
The minimum period of CO2 fixation from which a technology or NET project is recognised in terms of the Climate Strategy should be reflected.
NETs can only be used as a supplement to the priority reduction of greenhouse gas emissions when achieving the net zero target. Therefore, it is important that separate targets apply to the reduction of CO2 emissions and to CO2 removal.
Switzerland currently has a pioneering role in the development of NET. This competitive advantage should be further strengthened by promoting the relevant research and development, as well as demonstration projects.